This question should be asked in the Windows 8 Answers Forum at the following address
http://answers.microsoft.com/en-us/windows/forum/windows_8
Anyway, remember that Windows 8 is still something closer to a beta than a complete operating system: some features (like hardware and software support) are not completed and cannot work properly.
As a work around, you could try using Windows 7 audio drivers.
Bye.
Luigi Bruno - Microsoft Community Contributor 2011 Award